Maybe this is a boost in performance, but it’s hard to say. The amp shopping vid intro is 10-11 seconds straight of 16ths @ approximately 210, and it all looks pretty easy. The 250 vid is just one measure at a time… Troy might’ve been able to burst that out back in the day, as well, had he tried.
I’ll preface my response by saying that I think Troy is absolutely the man, and has had an incredibly massive impact on how we even think about technique. I’ve been following his work since before Cracking the Code was even officially a thing. But, you’ll see qualifiers like “in theory” thrown around a lot when talking about extreme RDT, and I know several long-time members here don’t get any performance boost from tall mouse over small mouse.
As for the trailing edge extreme metal guys, I still think this is just an outlier and they pick that way only because leading edge feels weird to them for whatever reason. For every one Dean Lamb from Archspire, there are multiple Dallas Toler-Wades and the guys from Suffocation.
Personal anecdote: a couple of years ago I had a student, and we developed a trailing edge technique for him. But this was clearly due to anatomical reasons - despite being relatively tall at around 6’1", he had proportionately short thumbs compared to the rest of his fingers. So, for him, trailing edge led to improved performance, but only because leading edge performance was basically impossible without discomfort.